Implementation trait for class path.FreeSpec, which is
a sister class to org.scalatest.FreeSpec that isolates
tests by running each test in its own instance of the test class, and
for each test, only executing the path leading to that test.

Implementation trait for class path.FunSpec, which is
a sister class to org.scalatest.FunSpec that isolates
tests by running each test in its own instance of the test class,
and for each test, only executing the path leading to that test.